The present invention relates to imaging devices and, more particularly, to high-dynamic-range imaging systems.
Image sensors are commonly used in electronic devices such as cellular telephones, cameras, and computers to capture images. In a typical arrangement, an electronic device is provided with an image sensor having an array of image pixels and a corresponding lens. Some electronic devices use arrays of image sensors and arrays of corresponding lenses.
In certain applications, it may be desirable to capture high-dynamic range images. While highlight and shadow detail may be lost using a conventional image sensor, highlight and shadow detail may be retained using image sensors with high-dynamic-range imaging capabilities.
Common high-dynamic-range (HDR) imaging systems use a multiple exposure (ME) image capture method. In a ME method, multiple images are captured by the image sensor, each image having a different exposure time. Short-exposure images may retain shadow detail while long-exposure images may retain highlight detail. In a typical device, image pixel values from short-exposure images and long-exposure images are selected to create an HDR image.
When combining sequentially captured images to form HDR images using conventional multiple exposure HDR image combination methods, changes in position of moving objects in the multiple images can result in motion artifacts in the combined HDR image.
It would therefore be desirable to provide improved imaging systems with motion-compensation capabilities for high-dynamic-range imaging.